CGAL users discussion list

[Marc Eder <>]

I didn't finish that thought.... That would help you to narrow down the space to only parallel planes. Then, you can either iterate over all of them and compute the projected distance. Or, if there's still a ton, you can always take the overhead of AABB trees on just these faces, and then choose the closest with `closest_point_and_primitive()`.

On Fri, Oct 25, 2019 at 10:41 AM Marc Eder <> wrote:

While I'm not sure if this is possible as I'm far from in-depth-experienced with CGAL.... I suspect you can build a custom AABB tree around face normals (just parameterize each normal as a point on a unit sphere (S2)). Then, look for the closest point in that AABB tree, treating your query point normal also as a point on the unit sphere.

On Fri, Oct 25, 2019 at 10:36 AM Andreas Fabri <> wrote:

I do  not see where that helps.  A point coplanar to a face  f
can be far away from f and be close to a non-coplanar face.

      ************
      *                      *
 p   f1                     ***f2**
      *                                    *
      ******************   

p is coplanar with f2 but f1 is closer

On 10/25/2019 4:27 PM, Sebastien Loriot (GeometryFactory) wrote:

You can use AABB_tree::closest_point_and_primitive()

https://doc.cgal.org/latest/AABB_tree/classCGAL_1_1AABB__tree.html#a1b3ac9521fd7257f760deafff3743437

Sebastien.

On 10/24/19 6:05 PM, aseverino wrote:

Hello,

I'm trying to find the face index that has its points coplanar to another
given point. This given point is guaranteed to be coplanar to the mesh
*somewhere*.

Is there a more optimized method to find that face without having to iterate
over all of them (in the worst case)?



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